Back in the day I'd replace DOS/4GW with PMODE/W, it includes the tools to bind/unbind the stub.

vstrakh wrote on 2025-03-02, 10:52:

Back in the day I'd replace DOS/4GW with PMODE/W, it includes the tools to bind/unbind the stub.

Dos32a came with sb. Exe which does the same thing, but it doesn't seem to correctly identify the exe type.

It should work with LE (Linear Executable) format, but not sure if .LC is the same... maybe compressed?

ripsaw8080 wrote on 2025-03-02, 21:39:

It should work with LE (Linear Executable) format, but not sure if .LC is the same... maybe compressed?

"LC" is DOS32A's variant on a compressed LE/LX file, or its intermediary file format when you bind sometimes.

Even running directly fails with:

1V:\CR>dos4gw cart.exe
2DOS/4GW Protected Mode Run-time Version 1.97
3Copyright (c) Rational Systems, Inc. 1990-1994
4DOS/4GW fatal error (1008): can't load executable format for file CART.EXE [1]
5
6V:\CR>dos32a cart.exe
7DOS/32A -- Protected Mode Run-time Version 7.35
8Copyright (C) Supernar Systems, Ltd. 1996-2005
9DOS/32A fatal (3006): exec format not supported in file "cart.exe"

It's almost like Dos4gw is static linked into the game.

There's supposed to be a PATH hack which allowed embedded versions to be overriden. How does that work? Is it as simple as adding it to the path?

I've figured out why SB.exe isn't working.

The first exec section is an MZ which is incompatible, the second is a BW. SB.exe, which replaces the stub doesn't test to see if the second exec is BW; if the first is incompatible it looks for LE, LX and LC as the second exec, but not BW, which is a supported type.

Base MZ, extended , start 00000000, size 0000F474
Base BW, extended , start 0000F474, size 008FB400

The second exec is a PE/COFF or whatever but there's no sign of an LX, LC or LE in there.

Does this mean Dos4gw is statically linked?

A hint would be to check the file size. Is the exe so large it could house a DOS4GW.exe in it?

BW are watcom EXP's. I think run386.exe runs them. fading memories but they mighty be pharlap or causeway extender files. You used to see the more with DOS16M instead of DOS4GW.

dos4gw should still be able to load a BW.

BloodyCactus wrote on 2025-03-04, 13:11:

BW are watcom EXP's. I think run386.exe runs them. fading memories but they mighty be pharlap or causeway extender files. You used to see the more with DOS16M instead of DOS4GW.

dos4gw should still be able to load a BW.

Well it's the second exec, the first is a 64kb mz.

Dos4gw and dos32a can't run it.

[edit] it only runs with it's built-in dos4gw in the 2nd exec. I have a bad feeling I can't replace the built in one with dos32a. The dos4gw binary and the actual game seem to be merged together.

use UNP utility to copy off the overlay then rebind (copy /b newstub.exe+overlay.bw newexec).

BloodyCactus wrote on 2025-03-04, 14:07:

use UNP utility to copy off the overlay then rebind (copy /b newstub.exe+overlay.bw newexec).

I'm a bit new to this, the stub from dos32a is the mz section from dos32a. Exe?

[edit]
Also which extender does unp come with? Dos32a comes with sb. Exe.

unp is its own tool. it has options to copy/remove overlays so you can use it to copy the overlay off to its own file.

https://bencastricum.nl/unp/unp411.zip

1V:\UNP411>unp o v:\cr\cart.exe v:\cr\cart.ovl
2
3UNP 4.11 Executable file restore utility, written by Ben Castricum, 05/30/95
4
5processing file : V:\CR\CART.EXE
6DOS file size 1247899
7file-structure  executable (EXE)
8EXE part sizes: header 512 bytes, image 62068 bytes, overlay 1185319 bytes
9action: copying overlay ... done
10new file size: 1185319
11writing to file : V:\CR\CART.OVL
12
13V:\UNP411>cd \cr
14
15V:\CR>dos4gw cart.ovl
16Illegal command: dos4gw.
17
18V:\CR>dos32a cart.ovl
19DOS/32A -- Protected Mode Run-time Version 7.35
20Copyright (C) Supernar Systems, Ltd. 1996-2005
21DOS/32A fatal (3004): exec format not supported in file "cart.ovl"

[EDIT] Running cart.exe does work with its own dos4gw, embedded into the overlay.
[EDIT2] How can I extract the stub from dos32a?
[EDIT3] Nm, Dos32A comes with a stub:

1V:\CR>copy /b v:\dos32a\dos32a\binw\stub32a.exe+ v:\cr\cart.ovl v:\cr\cart2.exe
2STUB32A.EXE
3CART.OVL
41 File(s) copied.
5
6V:\CR>cart2
7DOS/32A -- Protected Mode Run-time Version 7.35
8Copyright (C) Supernar Systems, Ltd. 1996-2005
9DOS/32A fatal (3006): exec format not supported in file "V:\CR\CART2.EXE"

weird. it should have worked. Ive done this many many times before.

Does anyone know if there's any documentation for watcom exp binary formats. I seem to be struggling to find anything. I'd like to try converting it to an mz/LE if possible .

sb.exe utility has wrong algorithm for finding executable headers. Instead of finding LE header at offset 0x28C9C, it finds what it thinks is a LC header (but it's not) at offset 0x7A35B.
You must unbind the linear executable manually, then you can bind it (using sb.exe) to dos32a.
Here is my algorithm to find the linear executable header.

M-HT wrote on 2025-03-07, 08:57:

sb.exe utility has wrong algorithm for finding executable headers. Instead of finding LE header at offset 0x28C9C, it finds what it thinks is a LC header (but it's not) at offset 0x7A35B.
You must unbind the linear executable manually, then you can bind it (using sb.exe) to dos32a.
Here is my algorithm to find the linear executable header.

Thanks will give that a go as soon as I get back to my desk.